Methane can be produced via CO and CO2 methanation. However, the CO2 methanation is more relevant in the context of Power-to-Gas (PtG) applications. The two methanation reactions are accompanied by further reactions such as the reverse water gas shift reaction and the Boudouard reaction. Looking at the overall stoichiometry the CO2 methanation can be seen as the combination of the CO methanation with the reverse water-gas shift. The Boudouard reaction producing unwanted carbon deposits on methanation catalysts is a big challenge especially for the CO methanation but of minor importance for the CO2 methanation and therefore PtG applications.